1. Field of the Invention
The invention relates to a lubricating device for a turbomachine with a main oil pump mechanically connected to a central rotor shaft, which main oil pump includes an input port connected to a suction line and a discharge port connected to a discharge line, as well as an oil pump unit, disposed in the region of the oil container, and which oil pump unit is hydraulically driven and includes a motor and a pump, where the motor of the oil pump unit is driven by the oil flowing out of the discharge line of the main oil pump, where the pump is mechanically driven by the motor, and where the pump withdraws oil from the oil container.
2. Brief Description of the Background of the Invention Including Prior Art
A lubricating device of the above-recited kind is known from the German Patent Application Laid Open DE-OS 3,522,595. This lubricating device includes a centrifugal main pump, which centrifugal main pump is mechanically connected with the central rotor shaft of the turbo-engine. The oil of the centrifugal main pump, flowing through the discharge line, drives a booster pump disposed in the oil container, where the booster pump includes a booster turbine section and a booster pump section, where the booster pump section withdraws oil from the oil container and pumps the oil into a suction line of a centrifugal main pump. The oil flowing out of the booster turbine section is fed via a regulating valve to a main supply line. In order to bridge over the deficiency power or, respectively, the zero transport of the centrifugal main pump, upon falling off of a minimum rotation speed of the rotor shaft, an auxiliary pump is disposed in the oil container as a positive displacement pump. This auxiliary pump is driven by a separate motor and draws oil from the oil container and pumps the oil into the main supply line. This lubrication system is very expensive in its construction and it is complicated in its automatic control mechanism, since each interruption of the transport of the lubricating oil, upon falling below the required minimum rotation speed for the centrifugal main pump, has to be balanced in another way and since an auxiliary pump has to be installed for bridging the interrupted transport power. The drive of the auxiliary pump is dependent on the rotation motion of the central rotor shaft and uses additional energy.